Coronary artery disease (CAD) is a major cause of morbidity and mortality worldwide. Recent interest has focused on chronic infectious diseases such as periodontal infection as potential contributors to CAD since traditional risk factors including hypercholesterolemia, smoking, and hypertension fail to fully explain the incidence of CAD. Epidemiological studies indicate that individuals with periodontal infection are 30 to 100% more likely to have CAD. During the past funding cycle, our findings linked NOD2, exposure to oral Porphyromonas gingivalis (P.g.), ApoE, and fatty diets with inflammatory changes to both bone loss and atherosclerosis. ApoE-/- mice injected i.p. with MDP to stimulate NOD2 and given weekly oral gavage of P.g. for 15 weeks displayed a reduction of serum cholesterol, inflammatory cytokines, alveolar bone loss, and atherosclerotic lesions in the aorta and aortic sinus compared with ApoE-/- mice orally challenged with P.g. but injected with saline. NOD2 deficiency in this model significantly aggravated bone loss and atherosclerosis. While MDP is an interesting target for therapeutic discovery, analogs with higher anti-inflammatory activity (e.g.TNF) and enhanced pharmacokinetic stability are certainly required. This is further justified by the side effects of the current anti-TNF-? antibody therapies. We have recently generated novel MDP analogs and identified a candidate with significant anti-TNF and NF?B properties. Active MDP analogs will be used to help characterize the pathway responsible for the MDP anti-inflammation property. To test our hypothesis we propose the following aims: Aim 1. Optimizing biological activity of MDP: We will continue medicinal chemistry and biochemical screening efforts to obtain a selective anti-inflammatory MDP compound(s) and optimize several scaffolds based on MDP. Aim 2. Determine signaling pathways of MDP and MDP analogs; and Aim 3. Preclinical testing of optimized compounds: A limited number of MDP analogs found in vitro to robustly reduce TNF production will be tested in our murine models of periodontal disease (PD) and atherosclerosis. Our goal is to elucidate the mechanism of action of optimized MDP compounds, a step towards identifying novel anti-inflammatory compounds suitable for clinical development. This will position us to apply this understanding in a human clinical trial setting, where we have considerable experience.